The Regional Water Resource Carrying Capacity Of Shale Gas Development: Based On System Dynamic Model

With the increasing of global energy demand and the gaming of international energy,the exploration of shale gas has gotten the world’s attention.United States is the world’s first and only country to achieve large-scale commercial production of shale gas.Countries around the world need to study and summarize the relevant skills and experience of United States in the areas of early assessment,exploration and development and pilot testing.At present,the main skill of shale gas exploration is hydrofracturing method,which is using high pressure to inject the mixtures of water,chemicals and sediment into underground wells,fracturing the shale rock formations,so that shale gas could be released into the wellhead,realizing the efficiency and economy of shale gas mining.In addition,a large amount of water has also been used to clean the cooling bit and other shale gas development process.Due to the scarcity of fresh water resources and the increasing demand of living water,industrial water and agricultural water,the use,handling and protection of water resources in shale gas development gets more and more attention.How to analyze the capacity of shale gas development considering regional water resources using scientific models and empirical data has become an important topic.This paper firstly analyzes the whole water resources dynamics system of shale gas development.Secondly it explores the key influence factors of shale gas water resources demand and freshwater resources consumption,and then finds the nonlinear relationships between demands and factors.Thirdly,the water resources bearing capacity system dynamics model of regional shale gas development is built,including water resources subsystem,population development subsystem,industry development subsystem and shale gas development subsystem.Furthermore,a complex network model is constructed for analyzing the roles and relationships of the elements in the model,in order to make the structure of network clearer.Finally,this paper tests,corrects and simulates the above models in different scenarios using the empirical data of Marcellus shale gas field Bradford County,and proposes the relevant policy recommendations on the shale gas development in China.The conclusions are as follows:(1)For China lack of water resources,due to the huge demand of water resources in shale gas mining process,the use of living water and industrial water will be threatened.Therefore,it is necessary to analyze the situations of regional population and industry development,and the water demand of shale gas single well mining in advance so as to make reasonable plans of shale gas development.(2)Through the simulation analysis in different scenarios,three key factors have a significant effect on the water resources bearing capacity of shale gas development,which respectively are reflux ratio of shale gas,reuse ratio of shale gas and reuse of treated wastewater.Consequently,for China,some measures should be taken for increasing the water resources bearing capacity of regional shale gas development,for example,improving the water recycling technology,improving the reflux ratio and reuse ratio of shale gas,encouraging the use of treated wastewater in the development process and so on by making laws,regulations and subsidy policies.